The role of the spleen in endotoxin-induced liver injury

In these experiments, the role of the spleen in endotoxin-induced liver injury was evaluated, using rats which underwent splenectomy or splenic vein ligation with antecedent spleno-systemic shunt. Male Wistar rats were divided into three groups: a sham-operated group, a splenectomy group, and a splenic vein ligation group. In each animal, 48 h after surgery, 5 mg/kg lipopolysaccharide (LPS) were injected intravenously. Six rats from each group were sacrificed 6 or 12 h after LPS administration. Bronchoalveolar lavage fluid (BALF) and arterial blood were also collected. Splenectomy reduced the liver injury as indicated by the serum lactate dehydrogenase level. A decrease in liver tissue adenosine triphosphate and increase in lipid peroxide were induced by LPS administration and inhibited by splenectomy. Splenectomy also reduced alveolar protein release as indicated by the protein level in BALF. Splenic vein ligation provided similar protective effects on the liver, but did not affect lung injury. From these results, it appears that the spleen plays a significant role in endotoxin-induced liver injury, and a mediator derived from the spleen is likely associated with development of liver injury. This mediator may be cleared or inactivated by not only splenectomy but also splenic vein ligation.